Low Oil Pressure after warm up
#1
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Low Oil Pressure after warm up
Any answers would be greatly appreciated.
I just recently picked my car up from the shop. It had completely different LS1 rebuilt and put in place. The heads were rebuilt as well.
New LS7 Lifters, New oil pump, pickup, melling, o-ring, oil pan (mine was damaged). The motor is stock.
Does tuning make a difference with the problem listed below? (i wouldnt think so but who knows)
The shop informed me NOT to worry about the piston slap the motor has. "Its normal in some motors, as mine does the same thing"
After starting the car for the first time from the shop it had about 70 for oil pressure. Once it warmed up it lowered to around 50. Giving it some gas would increase oil pressure as one would expect. The temperature outside was around 75 degrees. By the time i reached about 150 miles down the road (continuous driving) the car would idle at 5 oil pressure, peak at 20, and cruising at about 10 to 12 @ 1500 RPM. I accelerated to allow the RPM's to reach 3500 and heard not pleasant noises. I do not know how to describe as i let off the gas immediately.
I let the car sit for 24 hours and started it up. Temperature outside was about 85+ degrees. Oil pressure was at about 65. I drove it around heard no noises except for the "piston slap" the shop told me about, accelerated to about 3500 to 4000 RPM, the motor felt strong. after about 5 minutes of driving and mild acceleration I watched as the oil pressure got lower and lower. To where i didn't feel comfortable in pushing in the gas hoping it would show an increase on the gauge. A total of 7 to 10 minutes of the car even being on and oil pressure was down to around th 5 area. Low enough to cause the engine light to come on.
According to the shop EVERYTHING is different on this motor as nothing was usable on my old one...(I damaged it pretty bad)
I just recently picked my car up from the shop. It had completely different LS1 rebuilt and put in place. The heads were rebuilt as well.
New LS7 Lifters, New oil pump, pickup, melling, o-ring, oil pan (mine was damaged). The motor is stock.
Does tuning make a difference with the problem listed below? (i wouldnt think so but who knows)
The shop informed me NOT to worry about the piston slap the motor has. "Its normal in some motors, as mine does the same thing"
After starting the car for the first time from the shop it had about 70 for oil pressure. Once it warmed up it lowered to around 50. Giving it some gas would increase oil pressure as one would expect. The temperature outside was around 75 degrees. By the time i reached about 150 miles down the road (continuous driving) the car would idle at 5 oil pressure, peak at 20, and cruising at about 10 to 12 @ 1500 RPM. I accelerated to allow the RPM's to reach 3500 and heard not pleasant noises. I do not know how to describe as i let off the gas immediately.
I let the car sit for 24 hours and started it up. Temperature outside was about 85+ degrees. Oil pressure was at about 65. I drove it around heard no noises except for the "piston slap" the shop told me about, accelerated to about 3500 to 4000 RPM, the motor felt strong. after about 5 minutes of driving and mild acceleration I watched as the oil pressure got lower and lower. To where i didn't feel comfortable in pushing in the gas hoping it would show an increase on the gauge. A total of 7 to 10 minutes of the car even being on and oil pressure was down to around th 5 area. Low enough to cause the engine light to come on.
According to the shop EVERYTHING is different on this motor as nothing was usable on my old one...(I damaged it pretty bad)
#2
Piston slap usually goes away after 5-10 minutes when the motor warms up, oil pressure could be a number of things.....poorly fitted bearings can cause low pressure, bad oil pump, crappy/lod low viscosity oil
Piston slap can also be confused with Rod knock from a spun bearing(which could cause low oil pressure)
Piston slap can also be confused with Rod knock from a spun bearing(which could cause low oil pressure)
#3
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Damn, thats not good man. That damn o-ring can get pinched while installing the oil pump and cause oil pressure problems. The best builders do it sometimes and alot of the so-so builders do it.
If I were you I wouldn't start that thing again. Although, 150+ miles already, if your pressure and oil flow got too low you could have already scored the bearings. That shop needs to tear it down and see whats wrong in there....because something IS WRONG. Could just be the oil pump o-ring. At least its covered...RIGHT???? You did get a warranty, right?
.
If I were you I wouldn't start that thing again. Although, 150+ miles already, if your pressure and oil flow got too low you could have already scored the bearings. That shop needs to tear it down and see whats wrong in there....because something IS WRONG. Could just be the oil pump o-ring. At least its covered...RIGHT???? You did get a warranty, right?
.
#4
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That is definately a problem, I just recently did my H/C swap installed a new oil pump, I put a few shim washers in the pump, so mine shoots up to about 70 on startup, but after a while of running and heat in the engine at 1000 rpm idle i still have around 30 psi, your 5 psi is low, the old rule of thumb was 10 psi for every 1k of rpm. If they rebuilt your engine they should find the problem, that noise you referred to would have had me making an immediate bee-line back to the shop.
#5
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Damn, thats not good man. That damn o-ring can get pinched while installing the oil pump and cause oil pressure problems. The best builders do it sometimes and alot of the so-so builders do it.
If I were you I wouldn't start that thing again. Although, 150+ miles already, if your pressure and oil flow got too low you could have already scored the bearings. That shop needs to tear it down and see whats wrong in there....because something IS WRONG. Could just be the oil pump o-ring. At least its covered...RIGHT???? You did get a warranty, right?
.
If I were you I wouldn't start that thing again. Although, 150+ miles already, if your pressure and oil flow got too low you could have already scored the bearings. That shop needs to tear it down and see whats wrong in there....because something IS WRONG. Could just be the oil pump o-ring. At least its covered...RIGHT???? You did get a warranty, right?
.
1st build was done with a 6.0 iron block it made it 150 miles, low oil pressure and started knocking. It burned up 4 quarts of oil.
2nd build with same 6.0 iron 3 days after. Still oil burning issue,
So I had heads ported and rebuilt. Still consumed the same amount of oil
Took it back countless number of times till finally \|/
3rd build with an LS1, got it back leaking power steering everywhere. it had great oil pressure, drove it around but started getting 30 oil pressure at the most no matter what RPM, this motor didnt burn oil but it leaked it everywhere, 1 quart per day. Low oil pressure continued.
Took it back again countless number of times
Shop said I was just being picky about my oil pressure. brought it in they ran some test with mechanical oil gauge, "fixed" leak, told me to go test it.
Took it on the highway and yes I tested it.... 2 rods went through the block wall, all the internals were destroyed. I didnt reach a speed over 90mph
4th Rebuild entirely different motor, lifters, heads, oil pump, etc.
got it back power steering leaking more, water pump leaking, minor oil consumption/loss (very very little) oil pressure is good when cold but after warm it is incredibly low.
1 year warranty and the shop has had it for half of it. and 6 months I have had it for has been spent practically begging them day after day to find time to look at it more.
So to answer that yes it has warranty, but the year is up. And I am not sure what good it would do anyway considering I have had this much trouble.
Help is truly needed
#7
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Wow, it sounds like these guys don't know what they are doing. I am surprised they were able to physically swap the engines to begin with. It is too bad the LS engines make so many normal noises because it does make it a lot harder to troubleshoot issues over the internet. Since you are out of warranty and I doubt they want to work anything out with you your best bet is to take it to someone else to get if fixed correctly. I am not sure that after 4 tries I would want them to help me any more. You may want to think about getting a lawyer but just so you know most people don't win unless the judge can tell the difference between a spark plug and an oil filter. They always side with the expert. Unfortunately It could be any number of things like the previous posters stated. Are you able to do any of the possible work needed yourself?
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#8
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Wow, it sounds like these guys don't know what they are doing. I am surprised they were able to physically swap the engines to begin with. It is too bad the LS engines make so many normal noises because it does make it a lot harder to troubleshoot issues over the internet. Since you are out of warranty and I doubt they want to work anything out with you your best bet is to take it to someone else to get if fixed correctly. I am not sure that after 4 tries I would want them to help me any more. You may want to think about getting a lawyer but just so you know most people don't win unless the judge can tell the difference between a spark plug and an oil filter. They always side with the expert. Unfortunately It could be any number of things like the previous posters stated. Are you able to do any of the possible work needed yourself?
#9
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So you can do some basic testing yourself then. I did some searching and there are some complaints of oil sending units going bad. You might want to hook up a mechanical gauge to make sure that you really are having problems. Another quick check would be to open the oil fill cap and see if you can see any oil flowing at all when it is running. Another thing I thought of is if they forgot to put in the oil diverter that goes in the rear of the engine behind the rear main cover. It looks like a barbell. It is hard to believe that you have a bad bearing or oil pump already. I have to assume they can do something right. It does sound like they don't have much experience with LS engines. I would expect the engine to be making some bad noises if the pressure is really that low. Are you going to contact them to see if they are willing to help with anything?
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So you can do some basic testing yourself then. I did some searching and there are some complaints of oil sending units going bad. You might want to hook up a mechanical gauge to make sure that you really are having problems. Another quick check would be to open the oil fill cap and see if you can see any oil flowing at all when it is running. Another thing I thought of is if they forgot to put in the oil diverter that goes in the rear of the engine behind the rear main cover. It looks like a barbell. It is hard to believe that you have a bad bearing or oil pump already. I have to assume they can do something right. It does sound like they don't have much experience with LS engines. I would expect the engine to be making some bad noises if the pressure is really that low. Are you going to contact them to see if they are willing to help with anything?
Here is the update. I have a mechanical oil gauge i just bought. Hopefully if I have the time I will put it on the beginning of this week.
Will let you know what happens...
Then the next thing is to figure out how bad this piston slap is...
#11
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I would not worry too much about the piston slap noise. These engines make a lot of normal noises. As long as it is not a rod knock or a louder thud noise you are fine. Ticking noises are all normal for the most part. Once you get the oil pressure fixed you could have someone listen to it that knows what normal noises sound like. Sorry to hear about their lack of motivation. Hopefully you get something out of them. Good luck and keep us posted.
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You are right a new shop would be desirable, but I dont have an additional $4k to spend again
Ok guys here is an update
I installed a mechanical oil gauge, changed out oil with fresh oil, on a cold startup it reads over 60psi
I let it sit idling for about 10 minutes and it eventually dropped to about 30psi
I decided to take it for a quick spin. I say I drove it about 10 minutes giving it gas but only accelerating to about 4500 RPM as I dont trust it. By the time I got 1 mile away from home and the mech gauge was reading ZERO however reving the motor to about 4500 RPM would increase oil pressure to about 25psi...
So.... What is everyones diagnosis
Ok guys here is an update
I installed a mechanical oil gauge, changed out oil with fresh oil, on a cold startup it reads over 60psi
I let it sit idling for about 10 minutes and it eventually dropped to about 30psi
I decided to take it for a quick spin. I say I drove it about 10 minutes giving it gas but only accelerating to about 4500 RPM as I dont trust it. By the time I got 1 mile away from home and the mech gauge was reading ZERO however reving the motor to about 4500 RPM would increase oil pressure to about 25psi...
So.... What is everyones diagnosis
#15
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Sorry to hear your oil pressure was still bad. Anything on the magnetic drain plug? O-Ring would be a good place to start. You could get another shop to check that out fairly easily. Should only take them 3 to 4 hours total. You could also have them check out the oil pump since they are in there. Oil pump is fairly cheap as well if you want to just have them replace it.
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Considering that when the car first starts and oil pressure is fine till it warms up.. I would have to lead its to much bearing clearance
Well they have no officially said they arent touching it anymore.. So much for warranty, so much for almost 4k being spent...
Thanks for all the help and ideas. everyone.. be careful in Houston, TX
Well they have no officially said they arent touching it anymore.. So much for warranty, so much for almost 4k being spent...
Thanks for all the help and ideas. everyone.. be careful in Houston, TX
#17
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Considering that when the car first starts and oil pressure is fine till it warms up.. I would have to lead its to much bearing clearance
Well they have no officially said they arent touching it anymore.. So much for warranty, so much for almost 4k being spent...
Thanks for all the help and ideas. everyone.. be careful in Houston, TX
Well they have no officially said they arent touching it anymore.. So much for warranty, so much for almost 4k being spent...
Thanks for all the help and ideas. everyone.. be careful in Houston, TX
#20
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Maybe a faulty sending unit? Although it is weird that it just steadily loses oil pressure. I would think that they have screwed up with the O-ring. If you don't lube it before putting it on it will get pinched everytime. This may be the problem with every single one of their "rebuilt" motors. I'm sure they aren't doing much rebuilding.